Biogenic emissions during a hot season day in Greece

Abstract

Vegetation emits a large number of organic compounds into the atmosphere. On regional, continental and global scale, these values are comparable to or exceed the non-methane volatile organic compound (NMVOC) emissions from anthropogenic sources. Biogenic emissions from forests are highly reactive towards the atmospheric oxidants OH, O3 and NO3 and, therefore, play a significant role in determining the oxidative capacity of the atmosphere. Therefore, an accurate estimate of biogenic fluxes is an important requirement for any air quality monitoring system. Biogenic emission fluxes are strongly influenced by air temperature and solar radiation and, as a consequence, maximum values occur during hot season days. Furthermore, the greater day-light/sunshine duration and foliage mass in the summer lead to the release of much higher emission quantities into the atmosphere. In the present paper, isoprene, monoterpenes and other VOC (OVOC) emissions from Greek forests are estimated for a specific day during hot season. The input data used for performing the calculations are forest area coverage data, foliar biomass densities, emission rates per vegetation type, and meteorological data at high resolution (hourly air temperature and solar irradiance). Emissions are estimated and spatially allocated in a 6 x 6 km grid at national level, taking into account the space that each tree species occupies into each cell, in addition to the prevailing meteorological conditions in it. The results are presented in gridded maps for the entire country. Furthermore, emissions are compared with NMVOCs released from road traffic, the major anthropogenic source of NMVOC emissions. © by PSP.